CLASSIFICATION OF PORPITA

PHYLUM :- COELENTRATA (Tissue grade, diploblastic and acoelomate. )

CLASS :-  HYDROZOA  (The hydroids and craspedote medusa )

ORDER :- SIPHONOPHORA (Polymorphic colonies with various polypoid and medusoid zooids.)

SUB-ORDER :- PHYSOPHORIDA (Upper end of colony contains float or pneumatophore, without swimming bells or bracts and with simplified cormidia. )

FAMILY :- CHONDROPHORAE (Float forms a disk like structure.)

GENUS :- Porpita

GEOGRAPHICAL DISTRIBUTION

  • It is found along the South Atlantic coast and occasionally near U.K. coast. 

HABIT AND HABITAT

  • Porpita is marine and colonial, found in warm seas.

PORPITA

GENERAL CHARACTERSTICS OF PORPITA

  • It superficially resembles a medusa. It is most modified siphonophore. The stem is shortened to a flat coenosarc which along with float forms a rounded disk having several concentric air chambers. 
  • Body is discoidal, enclosing a chambered, chitinous and porous shell, having air corresponding with pneumatophore of Physalia
  • A large gastrozooid, having central mouth is encircled by several blastostyles. 
  • Margin of disk contains numerous dactylozooids or tentacles armed with nematocysts.
  • Nectocalyces or swimming bells are absent. 
  • Each air chamber opens to outside by a pair of pores.
  • Space between the gastric cavity of the gastrozooid and the pneumatophore is occupied by a large cellular mass traversed by canals, the so-called liver, supposed to have an excretory function. 
  • The reproductive zooids are liberated as free medusae.
PORPITA

IDENTIFICATION

  • The animal has central disc surrounded by tentacles and all above feature, hence it is Porpita.
PORPITA
PORPITA
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